*{
    margin: 0;
    padding:0;
}
body{
    background: #ccc;
}
li{
    list-style: none;
    width: 70px;
    text-align: center;
}

.box{
    height: 200px;
    width: 300px;
    margin: 100px auto;
}
.nav_head ul li,
.nav_body ul li{
    float: left;
}
.nav_body::after,
.nav_head::after{
    content: "";
    display: block;
    height: 0;
    clear: both;
    overflow: hidden;
    visibility: hidden;
}
.nav_head ul li:nth-child(-n+2),
.nav_body ul li:nth-child(-n+2){
    margin-right: 10px;
}
.nav_body ul li:nth-last-child(-n+2){
    display: none;
}
.nav_body{
    margin-top: 10px;
}
.nav_head ul li{
    cursor: pointer;
}
.chose{
    border-bottom: 1px solid rgb(87, 87, 230);
}